The easiest way would be to store pics on a photo storage web site. Photobucket.com used to be one of the best but began charging. IMGUR.com is what I use and it allows free photo editing/storage and copying of forum links into your message on this forum.
When it comes to your pc,the insert image icon is in the row of icons above your comment. Maybe you've tried going that route, but if not press the icon, choose file and then upload. When you press advanced at the bottom of the reply box, your picture should be there. The picture will be saved on crappie.com and never disappear like if you copied a url link and something happened to the photo on the storage site.